The prior art is replete with liquid all purpose hard surface cleaning compositions which are generally comprised of two types. The first type is a particulate aqueous suspension having water-insoluble abrasive particles suspended therein, which particles are palpable. Some of the cleaners of this type suffer a stability problem while others have received poor acceptance by consumers because of their "gritty" feel which causes many people to be reluctant to use them for fear of scratching the surface to be cleaned. The second type is the liquid detergent without suspended abrasive and this latter type is often preferred by consumers. While the liquid hard surface cleaner without abrasives is generally a mixture of a surfactant and builder salt in an aqueous medium, the product formulations in the market place have varied widely in composition.
The presence of builder salts as an essential ingredient in all purpose hard surface cleaning compositions to improve cleaning and to maintain an alkaline pH range, is disclosed in U.S. Pat. Nos. 4,576,738 and 4,597,887, and in European Patent Application Nos. 0165885 and 0080749 and in UK Patent Application No. 2166153A.
However, these prior art all-purpose liquid detergents containing detergent builder salts or other equivalents tend to leave films, spots or streaks on cleaned unrinsed surfaces, particularly shiny surfaces such as glass or stainless steel. Thus, such liquids require thorough rinsing of the cleaned surfaces which is a time-consuming chore for the user.
In order to overcome the problem of rinsing associated with the prior art all-purpose liquids, U.S. Pat. No. 4,017,409 teaches that paraffin sulfonate with a reduced concentration of inorganic phosphate builder salt may be employed. However, such compositions are often unacceptable from an environmental point of view based upon the phosphate content. Phosphate-free all-purpose liquids have been disclosed which contain a major proportion of a mixture of anionic and nonionic detergents with minor amounts of glycol ether solvent and organic amine as shown in U.S. Pat. No. 3,935,130. This approach has not been completely satisfactory due to excessive foaming from the high levels of organic detergents necessary to achieve cleaning and due to deposition of soap residue on the cleaned surfaces, leading to residual streaks and spots.
In order to overcome the disadvantages associated with the builder salts, Japanese Patent Kokai No. 52-77111 and European Patent Application No. 0,151,517 have used organic acids to improve detergency of builder-free detergent compositions. These compositions also contain an organic solvent as an essential ingredient which functions to dissolve greasy soil and soap scum, i.e., to improve detergency. Japanese Patent No. 52-77111 uses one or more organic acids selected from the group consisting of glycolic acid, lactic acid, citric acid, malic acid and malonic acid. European Patent Application No. 0,151,517 uses at least one water-soluble dicarboxylic acid having a 5-7 carbon chain length, which includes glutaric, adipic and pimelic acids.
The inclusion of a grease-removing organic solvent in an all purpose liquid cleaner composition for the degreasing of hard surfaces, is also disclosed in the above cited patents as well as others. Cleaning compositions containing a high boiling water-miscible organic solvent such as propylene glycol or ethylene glycol-monobutyl ether are disclosed in GB Patent No. 2166153A; a binary solvent system of Pinane and an ethylene glycol--or propylene glycol--monoethyl or monobutyl ether is disclosed in U.S. Pat. Nos. 4,576,738 and 4,597,887; a dual solvent system of dipropylene glycol methyl ether and mineral spirits is disclosed in U.S. Pat. No. 4,673,524; and a propylene glycol monomethyl ether and/or dipropylene glycol monomethyl ether as a penetrant to penetrate road film is disclosed in U.S. Pat. No. 4,670,171.
The prior art also discloses acidic liquid cleaning compositions containing organic solvents. A microemulsion-based acid composition containing phosphoric ester surfactants, hydrocarbon solvents and phosphoric acid for use as an all-purpose metal surface cleaner is disclosed in U.S. Pat. No. 4,540,448. U.S. Pat. No. 4,501,680 discloses an acidic liquid detergent for cleaning ceramic tiles without eroding the grout between the tiles. This composition contains two acids (i.e., glutaric acid and phosphoric acid), a nonionic surfactant, and an organic solvent.
However, none of the above-cited prior art, including the acidic all purpose cleaners, provides cleaning compositions which simultaneously disinfect the hard surfaces being cleaned.
However, non-acidic disinfectant compositions containing the combination of a quaternary ammonium germicidal compound and a nonylphenolethylene oxide condensate in an aqueous solution are disclosed in U.S. Pat. No. 3,017,278 for use in sterilizing medical and dental instruments and in U.S. Pat. No. 3,052,604 for direct application to human and animal tissue surfaces to promote wound healing.
Also, U.S. Pat. No. 3,223,643 discloses a liquid acid detergent-sanitizer composition of pH 2.5-3.5 containing phosphoric acid, a C.sub.8 -C.sub.18 alkyl dimethyl benzyl ammonium chloride sanitizer, and an alkylaryl polyether alcohol having about 5 to 7.5 ethylene oxide units. The nonionic detergent and the quaternary ammonium compound are in a 1:1 ratio in the disclosed compositions.
U.S. Pat. No. 4,661,523 discloses a concentrated acidic disinfectant composition having a pH of 3.5-4 which contains a synergistic bactericidal mixture of aldehydes and a quaternary ammonium compound, phosphonocarboxylic acid, and an amino-polycarboxylic acid salt, in an aqueous or aqueous-organic solvent vehicle.
German Patent Appln. No. 3445901 discloses a disinfectant agent concentrate in an aqueous or aqueous-organic solvent medium containing a synergistic mixture of hydrogen peroxide, a quaternary ammonium compound, a biguanide as the antimicrobial disinfectant agent, a complexing agent such as alkane poly-phosphonic acids and salts thereof to stabilize the hydrogen peroxide, an acid such as boric acid or phosphoric acid in an amount to provide a pH of 3-7 and optionally a nonionic and/or amphoteric surfactant.
U.S. Pat. No. 3,223,643, U.S. Pat. No. 4,661,523 and German Patent Appln. No. 3445901 are all acidic disinfecting cleaners. However, all of these prior art compositions incorporate phosphate acids and consequently have associated problems concerning environmental safety.
None of the above-mentioned disinfectant cleaning compositions provide a stable acidic disinfectant all-purpose liquid cleaning composition with improved removal of soap scum in the absence of detergent builders, organic solvents and phosphate compounds. In addition, unlike the cleaning compositions of the present invention, the prior art compositions are unable to provide a cleaned surface such that the removal of soil during subsequent cleanings is significantly enhanced.